This invention relates to a method of and a device for controlling a reserve winding when winding thread onto a spool or core. The thread is fed to a spool from a delivery mechanism via a traversing device and the start or end of the thread is fixed to the spool.
It is known to have a reserve winding on a spool to make the thread end located on the spool available to hand at any time during the unwinding of the thread package. This enables continuous manipulation of many thread packages. That is, the thread end of one package is connected, during the unwinding of the same, with the thread beginning of the next package. The spools may be driven either by a friction roller or by a motor as in the case of precision winding machines.
A thread reserve winding can be wound in various ways. In one prior art method, thread is wound into a thread reserve winding in such a way that the thread is disposed in parallel or roughly parallel onto the spool. The thread is wound onto the spool at a length of about 8 to 10 mm and having about 7 to 12 windings. Such a reserve winding has the advantage that the thread end is easily released from the spool without damage and the following package can be easily connected to the thread. As the result of the parallel position of the thread in the reserve winding, however, the thread end is not fixed to the spool. Consequently, the reserve winding may accidentally slip and drop from the spool. For this reason, the free hanging thread must be fixed to the end of the spool. This is usually fixed by gluing it to the spool. This type of fixture is unreliable, complicated and involves an additional working operation.
In another prior art method, the reserve winding is produced more or less as a flange of thread. The thread end is wound on top of itself in an uncontrolled or random manner. The thread end is fixed and secured by superimposed thread windings. Thus, there is no additional fixing of the thread end. However, in order to release it, the thread end must be withdrawn below the thread flange out of irregularly placed thread windings. The position of the thread end below the reserve winding is left to chance during its irregular construction. Consequently, when the thread end is withdrawn, there is a risk that tangles will result and that the thread filaments may be stretched, torn or otherwise damaged. In particular, so-called capillary breakages are produced in the threads so that the thread has no longer the desired strength in the relevant part.